c语言中求课程总分、平均分。学生总分及平均分

1、

#include <stdio.h>

int main(void)
{
    int i, j;
    int a[6][2];
    puts("please input the elements of the 6 * 2 matrix.");
    for (i = 0; i < 6; i++)
    {
        for (j = 0; j < 2; j++ )
        {
            printf("a[%d][%d] = ", i, j ); scanf("%d", &a[i][j]);
        }
    }
    int majorsum[2] = {0};
    int majormean[2];
    for (i = 0; i < 2; i++)
    {
        for (j = 0; j < 6; j++)
        {
            majorsum[i] += a[j][i]; 
        }
        majormean[i] = majorsum[i]/6;
    }
    for (i = 0; i < 2; i++)
    {
        printf("majorsum[%d] = %d\n", i, majorsum[i]);
        printf("majormean[%d] = %d\n", i, majormean[i]);
    }
    puts("--------\n--------\n---------");
    int studentsum[6];
    int studentmean[6];
    for (i = 0; i < 6; i++)
    {
        for (j = 0; j < 2; j++)
        {
            studentsum[i] += a[i][j];
        }
        studentmean[i] = studentsum[i]/2;
    }
    for (i = 0; i < 6; i++)
    {
        printf("studentsum[%d] = %d\n", i, studentsum[i]);
        printf("studentmean[%d] = %d\n", i, studentmean[i]);
    }
    return 0;
}

 ↓

#include <stdio.h>

int main(void)
{
    int a[6][2];
    int i, j;
    puts("please input the elements of the 6 * 2 matrix.");
    for (i = 0; i < 6; i++)
    {
        for (j = 0; j < 2; j++)
        {
            printf("a[%d][%d] = ", i, j);
            scanf("%d", &a[i][j]);
        }
    }
    int majorsum[2] = {0};
    double majormean[2];
    for (i = 0; i < 2; i++)
    {
        for (j = 0; j < 6; j++)
        {
            majorsum[i] += a[j][i];
        }
        majormean[i] = majorsum[i]/6;
    }
    for (i = 0; i < 2; i++)
    {
        printf("majorsum[%d] = %d\n", i, majorsum[i]);
        printf("majormean[%d] = %.1f\n", i, majormean[i]);
    }
    puts("--------\n--------\n--------");
    int studentsum[6] = {};
    double studentmean[6];
    for (i = 0; i < 6; i++)
    {
        for (j = 0; j < 2; j++)
        {
            studentsum[i] += a[i][j];
        }
        studentmean[i] = studentsum[i]/2;
    }
    for (i = 0; i < 6; i++)
    {
        printf("studentsum[%d] = %d\n", i, studentsum[i]);
        printf("studentmean[%d] = %.1f\n", i, studentmean[i]);
    }
    
    return 0;
}